JP2006319242A - Exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a contact between composition apparatus even when a plurality of composition apparatus are supported by use of a gas spring. <P>SOLUTION: An image of a pattern is exposed to a substrate W on a projection optical system PL by use of a moving stage 40. This exposure apparatus comprises a first support device 300 for supporting the projection optical system PL by a pressure of a gas fed into a first gas chamber 300a; a second support device 58 for supporting the moving stage 40 by a pressure of a gas fed into a second gas chamber 180; and exhaust devices 70, 80 which prevent the interference between the projection optical system PL and the moving stage 40, by differing an air volume displacement of the first gas chamber 300a from an air volume displacement of the second gas chamber 180. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exposure apparatus, and more particularly to an exposure apparatus suitable for use when exposing a substrate through a projection optical system and a liquid.

Semiconductor devices and liquid crystal display devices are manufactured by a so-called photolithography technique in which a pattern formed on a mask is transferred onto a photosensitive substrate. An exposure apparatus used in this photolithography process has a mask stage for supporting a mask and a substrate stage for supporting a substrate, and a mask pattern is transferred via a projection optical system while sequentially moving the mask stage and the substrate stage. It is transferred to the substrate. In recent years, in order to cope with higher integration of device patterns, higher resolution of the projection optical system is desired. The resolution of the projection optical system becomes higher as the exposure wavelength used is shorter and the numerical aperture of the projection optical system is larger. Therefore, the exposure wavelength used in the exposure apparatus is shortened year by year, and the numerical aperture of the projection optical system is also increasing. The mainstream exposure wavelength is 248 nm of the KrF excimer laser, but the 193 nm of the shorter wavelength ArF excimer laser is also being put into practical use. Also, when performing exposure, the depth of focus (DOF) is important as well as the resolution. The resolution R and the depth of focus δ are each expressed by the following equations.
R = k1 · λ / NA (1)
δ = ± k2 · λ / NA ² (2)
Here, λ is the exposure wavelength, NA is the numerical aperture of the projection optical system, and k1 and k2 are process coefficients. From the equations (1) and (2), it can be seen that the depth of focus δ becomes narrower when the exposure wavelength λ is shortened and the numerical aperture NA is increased in order to increase the resolution R.

If the depth of focus δ becomes too narrow, it becomes difficult to match the substrate surface with the image plane of the projection optical system, and the focus margin during the exposure operation may be insufficient. Therefore, as a method for substantially shortening the exposure wavelength and increasing the depth of focus, for example, a liquid immersion method disclosed in Patent Document 1 below has been proposed. In this immersion method, a space between the lower surface of the projection optical system and the substrate surface is filled with a liquid such as water or an organic solvent to form an immersion region, and the wavelength of exposure light in the liquid is 1 / n of that in air. (Where n is the refractive index of the liquid, which is usually about 1.2 to 1.6), the resolution is improved, and the depth of focus is expanded about n times.
International Publication No. 99/49504 Pamphlet

However, the following problems exist in the conventional technology as described above.
In order to realize the liquid immersion method, only a slight gap is allowed between the front lens of the projection optical system and the wafer sucked and held on the wafer table (wafer stage) so that the liquid can be held by surface tension. . For this reason, there is a possibility that the wafer may come into contact with the projection optical system or the liquid supply apparatus that supplies the liquid due to a runaway due to a bug in software for performing the exposure process, an uncontrollable state due to a power failure, an earthquake, or the like.

  Some of these projection optical systems and wafer tables are configured to be supported by a gas spring that supplies gas to the gas chamber. However, in this configuration, if an unexpected situation occurs, for example, an earthquake shakes. As a result, the device supported by the gas spring may come into contact with other structures and be damaged. Therefore, when such a situation occurs, it is preferable to quickly exhaust from the gas chamber to quickly stabilize it. However, as described above, the gap between the front lens of the projection optical system and the wafer is preferable. Since there are only a few gaps, there is a high possibility that they will come into contact with each other.

  The present invention has been made in consideration of the above points, and an object of the present invention is to provide an exposure apparatus that can prevent contact between components constituting the exposure apparatus.

In order to achieve the above object, the present invention adopts the following configuration corresponding to FIGS. 1 to 7 showing the embodiment.
The exposure apparatus of the present invention is an exposure apparatus (EX) that exposes a pattern image onto a substrate (W) by a projection optical system (PL) using a moving stage (40), and is provided in a first gas chamber (300a). A first support device (300) that supports the projection optical system (PL) by the pressure of the supplied gas, and a second support device that supports the moving stage (40) by the pressure of the gas supplied to the second gas chamber (180). (58) and the displacement of the first gas chamber (300a) are different from the displacement of the second gas chamber (180) to prevent interference between the projection optical system (PL) and the moving stage (40). And an exhaust device (70, 80).

  Therefore, in the exposure apparatus of the present invention, the first gas chamber (300a) and the second gas chamber (180) are exhausted in order to stabilize the projection optical system (PL) and the moving stage (40). By making the displacement of the first gas chamber (300a) and the displacement of the second gas chamber (180) different by the devices (70, 80), the interference between the projection optical system (PL) and the moving stage (40).・ Collision can be prevented.

  The exposure apparatus of the present invention further includes a substrate stage (40) on which the substrate (W) is placed, and a liquid supply device (1) that supplies the liquid (LQ1) to the substrate (W), and the liquid (LQ1). A first support device (300) that supports the liquid supply device (1) by the pressure of the gas supplied to the first gas chamber (300a) in the exposure device (EX) that exposes the pattern to the substrate (W) via The second support device (58) that supports the substrate stage (40) by the pressure of the gas supplied to the second gas chamber (180), and the displacement of the second gas chamber (180) are set to the first gas chamber (300a). And an exhaust device (70, 80) for preventing interference between the liquid supply device (1) and the substrate stage (40).

  Therefore, in the exposure apparatus of the present invention, the first gas chamber (300a) and the second gas chamber (180) are exhausted in order to stabilize the liquid supply device (1) and the substrate stage (40). By making the exhaust amount of the second gas chamber (180) larger than the exhaust amount of the first gas chamber (300a) by the apparatus (70, 80), the space between the liquid supply device (1) and the substrate stage (40). , And the interference / collision between the liquid supply device (1) and the substrate stage (40) can be prevented.

  In order to explain the present invention in an easy-to-understand manner, the description has been made in association with the reference numerals of the drawings showing one embodiment, but it goes without saying that the present invention is not limited to the embodiment.

  According to the present invention, it is possible to avoid damage to each component device constituting the exposure apparatus.

An exposure apparatus according to an embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 is a schematic diagram showing the configuration of the exposure apparatus EX. The exposure apparatus EX moves the reticle (mask) R and the wafer (substrate) W in a one-dimensional direction in synchronization with each other and each shot region on the wafer W via the projection optical system PL while transferring the circuit pattern formed on the reticle R. This is a step-and-scan type scanning exposure apparatus, so-called scanning stepper.

  In the following description, the direction that coincides with the optical axis of the projection optical system PL is the Z-axis direction, and the synchronous movement direction (scanning direction) between the reticle R and the wafer W in the plane perpendicular to the Z-axis direction is the Y-axis direction. A direction (non-scanning direction) perpendicular to the Z-axis direction and the Y-axis direction is taken as an X-axis direction. Further, the directions around the X, Y, and Z axes are the θX, θY, and θZ directions, respectively.

  The exposure apparatus EX includes an illumination optical system 10 that illuminates a reticle with illumination light from a light source 5, a reticle stage 20 that holds a reticle R, a projection optical system PL that projects illumination light emitted from the reticle onto a wafer W, and a wafer. A wafer stage (substrate stage, moving stage) 40 for holding W, a main body frame 100 for holding the reticle stage 20 and the projection optical system PL, and a base frame 200 for supporting the main body frame 100 and the wafer stage 40 from below are provided. .

The illumination optical system 10 includes a housing 11 and optical components including a relay lens system, an optical path bending mirror, a condenser lens system, and the like disposed in a predetermined positional relationship therein. The laser beam emitted from the light source 5 is incident on the illumination optical system 10, and the cross-sectional shape of the laser beam is shaped and illumination light (exposure light) having a substantially uniform illuminance distribution is irradiated onto the reticle. The
The illumination optical system 10 is supported by an illumination system support column 12 that extends in the upward direction (Z direction) and is fixed to the upper surface of the second frame 120 that constitutes the main body frame 100.

The reticle stage 20 includes a reticle fine movement stage that holds the reticle R, a reticle coarse movement stage that moves integrally with the reticle fine movement stage in the X-axis direction, which is the scanning direction, with a predetermined stroke, a linear motor that moves these, etc. (Not shown). The reticle fine movement stage is formed with a rectangular opening, and the reticle R is held by vacuum suction or the like by a reticle suction mechanism provided around the opening. Further, the two-dimensional position and rotation angle of the reticle fine movement stage and the position of the reticle coarse movement stage in the X-axis direction are measured with high accuracy by a laser interferometer (not shown). Position and speed are controlled.
The reticle stage 20 is supported in a levitating manner on the upper surface of a second pedestal 120, which will be described later, constituting the main body frame 100 via a non-contact bearing (for example, a hydrostatic bearing) (not shown).

As the projection optical system PL, both an object plane side (reticle side) and an image plane side (wafer side) are telecentric, and a reduction system that reduces at a predetermined projection magnification β (β is, for example, 1/5) is used. . For this reason, when illumination light (ultraviolet pulsed light) is irradiated onto the reticle R from the illumination optical system 10, an image forming light beam from a portion illuminated by the ultraviolet pulsed light in the circuit pattern region formed on the reticle R. Is incident on the projection optical system PL, and a partially inverted image of the circuit pattern is formed in a slit-like or rectangular shape elongated in the Y-axis direction in the center of the field of view on the image plane side of the projection optical system PL for each pulse irradiation of ultraviolet pulse light ( The image is limited to a polygon. As a result, the partially inverted image of the projected circuit pattern is reduced and transferred to one resist layer of the plurality of shot regions on the wafer W arranged on the imaging plane of the projection optical system PL.
In addition, the projection optical system PL is provided with a flange 31 on an outer wall (lens barrel), and is inserted into a hole 111 provided in a first frame 110 (to be described later) that constitutes the main body frame 100. It is supported via the flange 31.

  The main body frame 100 includes a first frame 110 that supports the projection optical system PL and the like, and a second frame 120 that supports the reticle stage 20 and the like disposed above the projection optical system PL. The first pedestal 110 is made of a plate-shaped member, and includes a hole 111 formed slightly larger than the outer diameter of the cylindrical projection optical system PL. The projection optical system PL is inserted into the hole 111, Supports the projection optical system PL. The second pedestal 120 includes a support plate 121 on which the reticle stage 20 is placed, and a plurality of support columns 122 that extend downward from the lower surface of the outer peripheral portion of the support plate 121 and are connected to the first pedestal 110. In consideration of the stability of the second pedestal 120, the number of the support columns 122 is preferably three, but is not limited thereto. Further, the support board 121 and the plurality of support columns 122 may be structured to be coupled by fastening means such as bolts or may be formed integrally. And the support | pillar 122 is fastened with the 1st mount 110 by fastening means, such as a volt | bolt, and the 1st mount 110 and the 2nd mount 120 are comprised integrally. Note that the support column 122 and the first gantry 110 are adjusted and fastened so that the projection optical system PL supported by the first gantry 110 and the reticle stage 20 supported by the second gantry 120 are in a predetermined positional relationship. Is done.

  The foundation frame 200 is placed substantially horizontally on the floor F of the clean room via three leveling feet 211. The base frame 200 includes a base portion 201 on which the wafer stage 40 is placed, and a plurality of support columns 202 extending upward from the upper surface of the base portion 201 by a predetermined length. The main body frame 100 (and projection optical system PL, reticle stage 20) is levitated and supported on the support column 202 via the air mount 300. Note that the number of support columns 202 is preferably three in consideration of the stability of the main body frame 100, but is not limited thereto. In addition, the base portion 201 and the plurality of support columns 202 may have a structure that is connected by fastening means or the like, or may be a structure that is integrally formed. On the floor F, an earthquake detection sensor FS composed of an accelerometer or the like is installed. The result detected by the earthquake detection sensor FS is output to the control device CONT.

  The air mount 300 is a so-called air spring (gas spring), and the main body frame 100 is vibrated from the floor F on the base frame 200 by the pressure of air supplied from the gas supply system 70 described later to the air chamber 300a. Separated and supported. The air mount 300 includes an actuator (not shown) that drives the main body frame 100 in a non-contact manner, an accelerometer mounted on the main body frame 100, and a position sensor that detects the position of the main body frame 100 in a non-contact manner (both not shown). ) And an active vibration isolator that controls the position of the main body frame 100 while blocking floor vibration. Non-contact type actuators and position sensors constituting the active vibration isolator are employed to block the vibration of the floor F, and are separated from the main body frame 100 at a predetermined distance. Note that an active vibration isolator may be configured by omitting an actuator (not shown) and controlling the internal pressure of the air mount 300. In order to secure this predetermined distance, the main body frame 100 supported by the air mount 300 is regulated so that the amount of movement in the horizontal plane (XY plane) is about 1 to 2 mm. A stopper system 310 is provided to restrain the movement of the main body frame 100 so that the main body frame 100 does not move beyond the regulation when a large vibration is applied to the exposure apparatus EX due to an earthquake or the like.

The stopper system 310 is a device that regulates the movement of the main body frame 100, and as shown in FIG. 2, the stopper system 310 is erected on the extension portion 311 that extends in the horizontal direction from the first mount 110 and the support column 202. It is provided with the column 203, and is comprised from the extending part 311 and the engaging part 312 which is opposingly arranged by the predetermined clearance gap on the Z direction both sides. The stopper system 310 actually restricts the movement of the main body frame 100 for six axes (X, Y, Z, θX, θY, θZ), but only the restriction in the Z-axis direction will be described here.
In the engaging portion 312, springs 313 are arranged opposite to each other as elastic bodies that are elastically deformed with a predetermined stroke, located on both sides of the extending portion 311 in the Z direction.

  The wafer stage 40 is supported by the surface plate 21 and continuously moved in the Y-axis direction and stepped in the X-axis direction by a driving device such as a linear motor integrally with the wafer table WT, supported by the surface plate 21. And an XY stage 41 that can be moved slightly in the θZ direction. The surface plate 21 is supported on the base portion 201 constituting the base frame 200 via the leveling foot LF1. The leveling foot LF1 may be omitted. The XY stage 41 is provided with a self-weight canceller mechanism 58 (see FIG. 1) as described in Japanese Patent Application No. 2004-215439 previously filed by the applicant of the present application. This self-weight canceller mechanism has a support portion that supports the wafer stage 40 by applying an internal pressure to the bellows, and an air bearing portion that faces the moving surface 21a as a guide surface and floats the wafer stage 40 relative to the moving surface 21a. is doing.

  More specifically, as shown in the longitudinal sectional view of FIG. 3, the self-weight canceller mechanism 58 has a cylindrical shape with a lower end (−Z side end) opened and an upper end (+ Z side end) closed. A cylinder portion 170A and a piston portion 170B inserted into the cylinder portion 170A through the opening and movable relative to the cylinder portion 170A are provided, and are arranged at the center of gravity of the wafer stage 40. A substantially airtight space 180 is formed above the piston portion 170B inside the cylinder portion 170A. In the space 180, a rare gas such as helium or nitrogen, or air (for example, air is employed in this embodiment) from a gas supply system 80 (described later) through an opening (not shown) formed in a part of the cylinder portion 170A. Is supplied at positive pressure.

  The piston portion 170B includes a groove 174b formed on the lower end surface (the end surface on the −Z side), and a ventilation pipe line 174a that reaches from the upper end surface to the bottom surface and communicates with the groove 174b in a state of being reduced in a nozzle shape at the lower end portion. Is formed. And since the space 180 is a positive pressure space, air is ejected from the nozzle part of the lower end of the ventilation pipe line 174a, and the flow of gas arises in the groove | channel 174b. As a result, a kind of gas static pressure bearing (thrust bearing) is formed on the bottom surface of the piston portion 170B due to the static pressure of air (pressure in the gap) between the bottom surface of the piston portion 170B and the moving surface 21a of the surface plate 21. The piston part 170B is supported above the surface plate 21 in a non-contact manner.

  In addition, annular convex portions 172a and 172b are formed in the cylinder portion 170A in the vicinity of the lower end portion over the entire circumference of the inner peripheral surface with the concave groove 172d interposed therebetween. A through hole 172c is formed on the inner bottom surface of the concave groove 172d to communicate the internal space of the cylinder portion 170A with the outside. The piston portion 170B is formed in a state where four vent pipes 176a to 176d (only 176a and 176c are shown in FIG. 3) are dug down to the vicinity of the central portion in the height direction near the periphery of the upper end surface. In the vicinity of the lower end of each of the air ducts 176a to 176d, a throttle hole 178 communicating with the outside of the outer peripheral surface of the piston part 170B is formed so as to penetrate therethrough. The piston portion 170B is inserted into the cylinder portion 170A in a state where a predetermined clearance is formed between the outer peripheral surface and the annular convex portions 172a and 172b.

Similarly to the air duct 174a, air is ejected from the air ducts 176a to 176d through the throttle hole 178 to the annular convex portion 172b, so that the annular convex portion 172b and the piston portion 170B outer peripheral surface A predetermined clearance is formed between the annular convex portions 172a and 172b and the outer peripheral surface of the piston portion 170B by the static pressure of the air therebetween. That is, a gas static pressure bearing (radial bearing) is substantially formed on the peripheral wall of the piston portion 170B.
Accordingly, in the self-weight canceller mechanism 58, when the XY stage 41 is supported at the upper end portion, the self-weight is supported by the positive pressure in the space 180, and a thrust bearing is provided between the moving surface 21a of the surface plate 21. The clearance can always be maintained by the action. In addition, when a force in the tilting direction (θX, θY) acts on the XY stage 41, the clearance is maintained by the action of the radial bearing, so that the tilt of the XY stage 41 is absorbed.

As shown in FIG. 1, the gas supply system 70 includes an electromagnetic valve 71, a pipe 72 provided between the air supply source 90 and the electromagnetic valve 71, and a pipe provided between the air mount 300 and the electromagnetic valve 71. 73, a control valve 74 that is interposed in the pipe 72 and controls the amount of air (air pressure) supplied to the air mount 300 under the control of the control device CONT.
The solenoid valve 71 is constituted by a three-way valve controlled by the control device CONT. When energized, the piping 72 and the piping 73 are connected to each other, and the air controlled by the control valve 74 is supplied to the air mount 300 so as not to be energized. At the time (at the time of power failure), the pipe 73 and the exhaust pipe 75 whose one end is open to the atmosphere are communicated. A throttle 76 is interposed in the exhaust pipe 75.

Similarly, the gas supply system 80 includes an electromagnetic valve 81, a pipe 82 provided between the air supply source 90 and the electromagnetic valve 81, and a pipe provided between the space 180 of the self-weight canceller mechanism 58 and the electromagnetic valve 81. 83, a control valve 84 that is interposed in the pipe 82 and controls the amount of air (air pressure) supplied to the space 180 under the control of the control device CONT.
The electromagnetic valve 81 is configured by a three-way valve controlled by the control device CONT. When energized, the pipe 82 and the pipe 83 are connected to each other, and the air controlled by the control valve 84 is supplied to the space 180. At the time of power failure, the pipe 83 and the exhaust pipe 85 having one end open to the atmosphere are communicated. A throttle 86 is interposed in the exhaust pipe 85.
In the present embodiment, when the solenoid valves 71 and 81 are not energized, the amount exhausted from the space 180 via the throttle 86 is larger than the amount exhausted from the air mount 300 (air chamber 300a) via the throttle 76. Thus, the aperture diameters of the apertures 76 and 86 are set.

  As shown in FIG. 4, a plurality of actuators such as a voice coil motor are provided between the wafer table WT and the XY stage 41, and the wafer table WT is placed on the XY stage 41 by driving these actuators. On the other hand, it is possible to perform minute movements in the three directions of the Z-axis direction, the θX direction (rotation direction around the X axis), and the θY direction (rotation direction around the Y axis), and has 6 degrees of freedom as a whole. The position of the XY stage 41 in the XY direction and the rotation angle in the θX, θY, and θZ directions are determined by the laser interferometer 44 that irradiates the measurement surface to the + Y side reflection surface 41Y of the wafer table WT and Measurement is performed with high accuracy by a laser interferometer 42 that irradiates a measurement beam onto the reflection surface 41X, and the position and speed of the XY stage 41, and thus the wafer W, are controlled based on the measurement result.

  The driving device that drives the XY stage 41 drives the XY stage 41 with a long stroke in the X direction, and also includes a Y direction, a Z direction, θx (a rotation direction around the X axis), θy (a rotation direction around the Y axis), A first drive system 27 that finely drives θz (rotation direction around the Z axis) and second drive systems 28a and 28b that drive the XY stage 41 and the first drive system 27 in the Y direction with a long stroke are provided. . The base portion 201 is provided with protrusions FCa and FCb protruding upward in the vicinity of the ends of one side and the other side in the X direction with the Y direction as the longitudinal direction, and above the protrusions FCa and FCb. The Y axis stators 38a and 38b extending in the Y direction and constituting the second drive systems 28a and 28b are disposed, respectively. Movable elements 39a and 39b are inserted between the stators 38a and 38b from the inside of the stators 38a and 38b, respectively. These Y-axis stators 38a and 38b are levitated and supported above the protrusions FCa and FCb via a predetermined clearance by a static gas bearing (not shown) provided on each lower surface, for example, an air bearing. Yes. This is because the stators 38a and 38b move in the reverse direction as the Y counter mass in the Y direction due to the reaction force generated by the movement of the wafer stage 40 in the Y direction, and the reaction force is canceled by the law of conservation of momentum. is there.

  The second drive systems 28a and 28b are provided with a tube carrier 29 that moves integrally with the wafer stage 40 in the Y-axis direction and moves following the wafer stage 40 in the X direction. The tube carrier 29 relays various types of tubes supplied to the wafer stage 40 such as electric wiring and air supply pipes.

Between the tube carrier 29 and the wafer stage 40, a stopper system 320 having the same configuration as the stopper system 310 and restricting the movement of the wafer stage 40 is provided. As shown in FIG. 5, the stopper system 320 is provided on the side surface of the XY stage 41 and the extending portion 321 extending in the horizontal direction from the tube carrier 29, and has a predetermined gap on both sides of the extending portion 321 and the Z direction. It is comprised from the engaging part 322 arrange | positioned facing. In the stopper system 320 as well, the movement of the wafer stage 40 is actually restricted in the six-axis direction, but here only the restriction in the Z-axis direction will be described.
A spring 323 is disposed opposite to the engaging portion 322 as an elastic body that is located on both sides in the Z direction of the extending portion 321 and elastically deforms with a predetermined stroke.

  The exposure apparatus EX of the present embodiment is an immersion exposure apparatus to which an immersion method is applied in order to substantially shorten the exposure wavelength to improve the resolution and substantially widen the depth of focus. Among the plurality of optical elements constituting the PL, as shown in FIG. 6, a space K1 between the lower surface T1 of the optical element LS1 closest to the image plane of the projection optical system PL and the substrate P is filled with the liquid LQ1, and the liquid The liquid LQ2 fills the space K2 between the first immersion mechanism 1 that forms the immersion region LR1, the optical element LS1, and the optical element LS2 that is next to the optical element LS1 and close to the image plane of the projection optical system PL. It has the 2nd liquid immersion mechanism 2 which forms area | region LR2. The operations of the liquid immersion mechanisms 1 and 2 are controlled by the control device CONT.

The first immersion mechanism 1 includes a liquid supply unit 51, a nozzle member 7, a supply pipe 13 that supplies the liquid LQ 1 from the liquid supply unit 51 to the nozzle member 7, and a liquid recovery unit 61.
The liquid supply unit 51 includes a pure water production device, a temperature adjustment device that adjusts the temperature of the liquid (pure water) LQ1 to be supplied, and a deaeration device for reducing gas components in the liquid LQ1 to be supplied. . The liquid recovery unit 61 includes a vacuum pump, a gas-liquid separator, and the like that can recover the liquid LQ1 from the nozzle member 7 via the recovery pipe 23.

  In the middle of the supply pipe 13, an electromagnetic valve 16 that opens the supply pipe 13 to flow the liquid LQ1 when energized and closes the supply pipe 13 when not energized is interposed. Similarly, in the middle of the recovery pipe 23, an electromagnetic valve 17 that opens the recovery pipe 23 to flow the liquid LQ1 when energized and closes the recovery pipe 23 when not energized is interposed. Energization of these solenoid valves 16 and 17 is controlled by the control device CONT.

The nozzle member 7 is disposed in the vicinity of the image plane side of the projection optical system PL, specifically, in the vicinity of the optical element LS1 at the image plane side end of the projection optical system PL, and is projected above the wafer W (wafer stage 40). It is an annular member provided so as to surround the front end portion of the optical system PL, and is supported and mounted on the projection optical system PL (its barrel) via a support member PLa.
On the lower surface 7A of the nozzle member 7, a supply port 62 for supplying the liquid LQ1 onto the wafer W is provided. In addition, an internal flow path 14 that connects the connection portion of the supply pipe 13 and the supply port 62 is formed inside the nozzle member 7.
Further, a recovery port 22 for recovering the liquid LQ1 on the wafer W is provided on the lower surface 7A of the nozzle member 7. The recovery port 22 is annularly provided outside the supply port 62 with respect to the optical axis AX of the projection optical system PL so as to surround the supply port 62 on the lower surface 7A of the nozzle member 7. In addition, an internal flow path 24 that connects the connection portion of the recovery pipe 23 and the recovery port 22 is formed inside the nozzle member 7.

  The second immersion mechanism 2 is for supplying the liquid LQ2 to the space K2 between the optical element LS2 and the optical element LS1 of the projection optical system PL, and has substantially the same configuration as the liquid supply unit 51. The liquid supply unit 52 capable of delivering the liquid LQ2, the supply pipe 33 for supplying the liquid LQ2 from the liquid supply unit 52 to the supply flow path 34 formed inside the lens barrel PK, and the inside (inside of the lens barrel PK) A supply member 35 provided with a supply port 32 for supplying the liquid LQ2 to the space K2, a recovery member 45 provided with a recovery port 42 for recovering the liquid LQ2 in the space K2, and a liquid recovery unit 61, and a liquid recovery part 63 that recovers the liquid LQ2 via a recovery flow path 44 and a recovery pipe 43 formed in the interior of the lens barrel PK.

  In the middle of the supply pipe 33, an electromagnetic valve 18 is provided that opens the supply pipe 33 to flow the liquid LQ2 when energized and closes the supply pipe 33 when not energized. Similarly, in the middle of the recovery pipe 43, an electromagnetic valve 19 that opens the recovery pipe 43 to flow the liquid LQ2 when energized and closes the recovery pipe 43 when not energized is interposed. Energization of these solenoid valves 18 and 19 is controlled by the control device CONT.

  In the present embodiment, pure water is used as the liquid LQ1 supplied from the liquid supply unit 51 and the liquid LQ2 supplied from the liquid supply unit 52. That is, in the present embodiment, the liquid LQ1 and the liquid LQ2 are the same liquid. Pure water can transmit not only ArF excimer laser light but also far ultraviolet light (DUV light) such as bright lines (g-line, h-line, i-line) emitted from mercury lamps and KrF excimer laser light (wavelength 248 nm). It is.

  In the exposure apparatus of the present embodiment, the relative position between the projection optical system PL (and the nozzle member 7 of the first immersion mechanism 1) and the wafer W (wafer table WT), that is, the distance of the gap in the space K1 is detected. A detecting device 50 is provided. The detection result of the detection device 50 is output to the control device CONT.

  In the exposure apparatus EX configured as described above, when forming the liquid immersion area LR1 of the liquid LQ1 in the space K1, the control apparatus CONT sends out the liquid LQ1 from the liquid supply unit 51 with the electromagnetic valves 16 and 17 open. The liquid LQ1 is supplied to the space K1 on the wafer W from the supply port 62 provided above the wafer W via the supply pipe 13 and the internal flow path 14 of the nozzle member 7. Further, the liquid LQ1 in the space K1 is recovered from the recovery port 22 and recovered in the liquid recovery part 61 via the internal flow path 24 of the nozzle member 7 and the recovery pipe 23. Similarly, when forming the liquid immersion region LR2 of the liquid LQ2 in the space K2, the control device CONT sends out the liquid LQ2 from the liquid supply unit 52 with the electromagnetic valves 18 and 19 opened, and supplies the supply pipe 33 and the supply flow. The liquid LQ2 is supplied from the supply port 32 to the space K2 through the passage 34 and the internal flow path of the supply member 35. In addition, the liquid LQ2 in the space K2 is recovered from the recovery port 42 and recovered by the liquid recovery unit 63 via the internal flow path of the recovery member 45, the recovery flow path 44, and the recovery pipe 43.

  Then, the optical path space of the space K1 on the lower surface T1 side and the space K2 on the upper surface T2 side of the optical element LS1 is filled with the liquid LQ1 and the liquid LQ2, so that the lower surface of the optical element LS2 and the upper surface T2 of the optical element LS1 are filled. Thus, the wafer W can be satisfactorily exposed in a state where a large image-side numerical aperture is secured.

  That is, in the exposure apparatus EX, a resist pattern is applied to the surface of the circuit pattern in the illumination area of the reticle R at the projection magnification β via the projection optical system PL and the liquids LQ1 and LQ2 under illumination light. And projected onto a slit-like exposure area (an area conjugate to the illumination area) on the wafer W. In this state, the reticle R and the wafer W are synchronously moved in a predetermined scanning direction (X-axis direction), whereby the circuit pattern of the reticle R is transferred to one shot area on the wafer W.

  When such a normal operation is performed, the control device CONT opens the electromagnetic valve 71 with respect to the gas supply system 70 and pipes the air amount from the air supply source 90 controlled by the control valve 74. 72 and 73 are supplied to the air mount 300, and the projection optical system PL is supported via the first mount 110 by the supplied air pressure. Similarly, the control device CONT opens the electromagnetic valve 81 with respect to the gas supply system 80 and supplies the air amount from the air supply source 90 controlled by the control valve 84 to the self-weight canceller mechanism 58 via the pipes 82 and 83. The wafer stage 40 is supplied to the space 180 and supported by the supplied air pressure.

  Here, the gap between the space K1 on the wafer W, that is, the gap between the wafer W and the projection optical system PL (optical element LS1) or the gap between the wafer W and the nozzle member 7 is always detected by the detection device 50. The control device CONT monitors the solenoid valve 71 in the gas supply systems 70 and 80 when a runaway or the like due to a soft bug occurs and the gap distance becomes narrower than a threshold value. , 81 are closed (energization is stopped). Further, the control device CONT closes the control valves 74 and 84 in the first liquid immersion mechanism 1 and the second liquid immersion mechanism 2 to stop the supply of the liquids LQ1 and LQ2 to the spaces K1 and K2, and the spaces K1 and K2 The liquid is recovered by the liquid recovery units 61 and 63.

When the solenoid valves 71 and 81 are closed, the pipe 73 and the exhaust pipe 75 communicate with each other, and the air in the air mount 300 (air chamber 300a) is exhausted from the exhaust pipe 75, whereby the first mount 110 (and The projection optical system PL and the nozzle member 7) are lowered to the −Z side (downward). Also, the piping 83 and the exhaust pipe 85 communicate with each other, and the air in the space 180 of the self-weight canceller mechanism 58 is exhausted from the exhaust pipe 85, whereby the cylinder portion 170A (and the wafer stage 40) shown in FIG. Descend to the side (down). When the projection optical system PL, the nozzle member 7 and the wafer stage 40 are lowered, the amount per unit time exhausted from the space 180 through the diaphragm 86 is from the air mount 300 (air chamber 300a) through the diaphragm 76. Since it is larger than the amount per unit time to be evacuated, the wafer stage 40 descends at a speed higher than that of the projection optical system PL and the nozzle member 7.
That is, as the projection optical system PL, the nozzle member 7 and the wafer stage 40 are lowered, the distance between the spaces K1 increases, so that the projection optical system PL and the wafer W (wafer stage 40), the nozzle member 7 and the wafer are increased. Interference with W (wafer stage 40) is avoided.

  The sizes of the diaphragms 76 and 86 are such that the projection optical system PL, the nozzle member 7 (in this case, the first gantry 110) and the wafer stage 40 can be landed quickly to be in a stable state. It is set as large as possible so that the optical element is not displaced.

  When the projection optical system PL and the nozzle member 7 are lowered, the movement of the stopper system 310 shown in FIG. 2 is restricted by engaging the extending portion 311 extending from the first mount 110 with the engaging portion 312. Therefore, the impact at the time of descent stop when the moving distance of the first gantry 110 is long and the descent speed is increased is mitigated. When the engaging portion 312 is engaged, the extending portion 311 is actually engaged via the -Z side spring 313. At this time, the extending portion 311 is engaged while compressing and bending the spring 313. Therefore, the impact when the first mount 110 is lowered is absorbed.

  Similarly, when the wafer stage 40 and the wafer W are lowered, the movement of the stopper system 320 shown in FIG. 5 is restricted by the extension portion 321 extending from the tube carrier 29 engaging with the engagement portion 322. Therefore, the impact at the time of descent stop when the moving distance of the wafer stage 40 is long and the descent speed is increased is mitigated. Here, when the extended portion 321 is engaged with the engaging portion 322, the extended portion 321 is actually engaged via the spring 323 on the + Z side. At this time, while the spring 323 is compressed and bent, Because of the engagement, the impact when the wafer stage 40 is lowered is absorbed.

  When the exposure apparatus EX is shaken due to an earthquake or the like, the earthquake detection sensor FS detects the shake and outputs the shake to the control unit CONT. When the magnitude of the detected swing exceeds a predetermined threshold, the control device CONT uses the electromagnetic valves in the gas supply systems 70 and 80 in the same manner as when the gap in the space K1 on the wafer W is reduced. 71 and 81 are closed (energization is stopped), and the electromagnetic valves 16 and 17 in the first immersion mechanism 1 and the electromagnetic valves 18 and 19 in the second immersion mechanism 2 are closed (energization is stopped).

Thereby, it is possible to prevent the projection optical system PL and the nozzle member 7 from interfering with the wafer W (wafer stage 40) due to the earthquake. Further, in the process of landing the projection optical system PL, the nozzle member 7 and the wafer stage 40, they can be prevented from interfering with each other. In particular, by causing the earthquake detection sensor FS to detect a P wave (longitudinal wave) having a high propagation speed when an earthquake occurs, the projection optical system PL, nozzle member 7 and The wafer stage 40 can be landed and kept in a stable state.
In addition, when an earthquake shakes, the extension portions 311 and 312 engage with the engaging portions 312 and 322 via the springs 313 and 323 in the stopper systems 310 and 320, so the elasticity of the springs 313 and 323 is increased. Due to the deformation, it becomes possible to absorb an impact caused by the movement of the first mount 110 (that is, the projection optical system PL, the nozzle member 7) and the wafer stage 40.

Next, the operation during a power failure, including when an earthquake occurs, will be described.
Even when the power supply is interrupted due to a power failure, the electromagnetic valves 71 and 81 in the gas supply systems 70 and 80 are closed, so that the projection optical system PL, the nozzle member 7 and the wafer stage 40 are more optimal for the wafer stage 40 than the projection optical system. The system PL and the nozzle member 7 are lowered at a higher speed, and interference between the projection optical system PL and the wafer W (wafer stage 40) and between the nozzle member 7 and the wafer W (wafer stage 40) is avoided.

  Further, in the state where the power supply is stopped, the electromagnetic valves 16 to 19 are closed in the first liquid immersion mechanism 1 and the second liquid immersion mechanism 2, so the liquid filled in the spaces K 1 and K 2 and the electromagnetic valves 16 to 19. Further, leakage can be stopped only in the liquid in the pipes 13, 23, 33, 43 on the space K1, K2 side, the liquid supplied from the liquid supply units 51, 52, or the liquid recovery units 61, 63 in advance. It is possible to prevent a large amount of liquid leakage due to the liquid recovered in step S1 and flowing back to the spaces K1 and K2 and the like, and rust and electric leakage occur in peripheral devices of the wafer stage 40.

  As described above, in the present embodiment, the gas supply systems 70 and 80 cause the exhaust amount of the space 180 in the self-weight self-weight canceller mechanism 58 positioned below to be larger than the exhaust amount of the air chamber 300a in the air mount 300. Therefore, when an unexpected situation occurs, even when the projection optical system PL, the nozzle member 7 and the wafer stage 40 are landed, these interferences and collisions are prevented and each component is damaged. You can avoid that. Further, in the present embodiment, even when the power supply is stopped such as a power failure, the interference / collision of the projection optical system PL, the nozzle member 7 and the wafer stage 40 can be avoided without relying on software. Safe measures can be taken.

Further, in the present embodiment, since the movement of the projection optical system PL, the nozzle member 7 and the wafer stage 40 is restricted by the stopper systems 310 and 320, it is possible to alleviate a large impact applied when the descent (movement) is stopped. . In particular, in the present embodiment, the springs 313 and 323 are provided in the stopper systems 310 and 320 to absorb the impact when descending, so that damage to these components can be avoided more reliably.
Furthermore, in the present embodiment, as described above, the liquid supply is stopped by closing the supply pipes 13 and 33 by the electromagnetic valves 16 and 18 when an abnormality occurs in the exposure apparatus EX such as an earthquake, a runaway due to a soft bug, a power failure, etc. The collection pipes 23 and 43 are closed by the electromagnetic valves 17 and 19 to prevent the collected liquid from flowing backward, so that the leakage can be minimized, and a large amount of leakage occurs to the peripheral device of the wafer stage 40. Rust and leakage can be prevented.

  In this embodiment, the earthquake detection sensor FS senses, for example, a P wave, so that the projection optical system PL, the nozzle member 7 and the wafer stage 40 are landed in advance and stabilized before a large shake occurs. Thus, it is possible to more reliably avoid damage to the projection optical system PL, the nozzle member 7 and the wafer stage 40 due to a collision caused by shaking.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, although the extension part 321 in the stopper system 320 is provided in the tube carrier 29, it is not limited thereto, and may be provided in the first drive system 27 shown in FIG.

  In the above-described embodiment, the present invention has been described as being applied to the wafer stage 40. However, the present invention may be applied to the reticle stage 20. More specifically, in the above embodiment, the reticle stage 20 and the projection optical system PL are integrally supported by the air mount 300. However, as shown in FIG. 7, the air mount that supports the reticle stage 20 is used. 400 and the air mount 500 that supports the projection optical system PL can be applied separately.

  Further, as disclosed in JP-A-11-135400 and JP-A-2000-164504, a measurement stage equipped with a substrate stage for holding a substrate, a reference member on which a reference mark is formed, and various photoelectric sensors. The present invention can also be applied to a measurement stage in an exposure apparatus including the above.

In addition, although water can be used as the liquid in the present embodiment, it may be a liquid other than water. For example, when the light source of exposure light is an F ₂ laser, the F ₂ laser light transmits water. Therefore, the liquid may be, for example, a fluorine-based fluid such as perfluorinated polyether (PFPE) or fluorine-based oil that can transmit the F ₂ laser beam. In this case, the lyophilic treatment is performed by forming a thin film with a substance having a small molecular structure including fluorine, for example, in a portion that contacts the liquid. In addition, as the liquid, a liquid that is transparent to the exposure light, has a refractive index as high as possible, and is stable with respect to the projection optical system and the photoresist applied to the surface of the substrate P (for example, cedar oil). It is also possible to use it.

  A liquid having a refractive index of about 1.6 to 1.8 may be used. Furthermore, the optical element may be formed of a material having a refractive index higher than that of quartz or fluorite (for example, 1.6 or more).

  The substrate of each of the above embodiments is not only a semiconductor wafer for manufacturing a semiconductor device, but also a glass substrate for a display device, a ceramic wafer for a thin film magnetic head, or an original mask or reticle used in an exposure apparatus ( Synthetic quartz, silicon wafer) or the like is applied.

  As an exposure apparatus, in addition to a step-and-scan type scanning exposure apparatus (scanning stepper) that scans and exposes a mask pattern by synchronously moving a mask (reticle) and a substrate, the mask and the substrate are stationary. The present invention can also be applied to a step-and-repeat type projection exposure apparatus (stepper) in which a mask pattern is collectively exposed and the substrate is sequentially moved stepwise.

  As the exposure apparatus, a reduced optical image of the first pattern is projected with the first pattern and the substrate substantially stationary (for example, a refractive projection optical system that does not include a reflective element at 1/8 reduction magnification). The present invention can also be applied to an exposure apparatus that performs batch exposure on a substrate. In this case, after that, with the second pattern and the substrate being substantially stationary, a reduced image of the second pattern is collectively exposed on the substrate by partially overlapping the first pattern using the projection optical system. It can also be applied to a batch exposure apparatus of the type. The stitch-type exposure apparatus can also be applied to a step-and-stitch type exposure apparatus that partially transfers at least two patterns on a substrate and moves the substrate sequentially.

  The present invention also relates to a twin stage type exposure apparatus having a plurality of substrate stages as disclosed in JP-A-10-163099, JP-A-10-214783, JP-T 2000-505958, and the like. It can also be applied to.

  In the above-described embodiment, an exposure apparatus that locally fills the liquid between the projection optical system and the substrate is employed. However, the present invention is disclosed in JP-A-6-124873 and JP-A-10-303114. The present invention is also applicable to an immersion exposure apparatus that performs exposure in a state where the entire surface of a substrate to be exposed is immersed in a liquid as disclosed in US Pat. No. 5,825,043.

  The type of exposure apparatus is not limited to an exposure apparatus for manufacturing a semiconductor element that exposes a semiconductor element pattern on a substrate, but an exposure apparatus for manufacturing a liquid crystal display element or a display, a thin film magnetic head, an image sensor (CCD) or The present invention can be widely applied to an exposure apparatus for manufacturing a reticle or a mask.

  In the above-described embodiment, a light-transmitting mask in which a predetermined light-shielding pattern (or phase pattern / dimming pattern) is formed on a light-transmitting substrate is used. As disclosed in Japanese Patent No. 6,778,257, an electronic mask that forms a transmission pattern, a reflection pattern, or a light emission pattern based on electronic data of a pattern to be exposed may be used.

  Further, as disclosed in the pamphlet of International Publication No. 2001/035168, the present invention is also applied to an exposure apparatus (lithography system) that exposes a line-and-space pattern on a substrate by forming interference fringes on the substrate. The invention can be applied.

  When a linear motor (see USP5,623,853 or USP5,528,118) is used for the substrate stage or mask stage, either an air levitation type using air bearings or a magnetic levitation type using Lorentz force or reactance force may be used. . Each stage may be a type that moves along a guide, or may be a guideless type that does not have a guide.

  As a drive mechanism for each stage, a planar motor that drives each stage by electromagnetic force with a magnet unit in which magnets are arranged two-dimensionally and an armature unit in which coils are arranged two-dimensionally face each other may be used. In this case, any one of the magnet unit and the armature unit may be connected to the stage, and the other of the magnet unit and the armature unit may be provided on the moving surface side of the stage.

As described in JP-A-8-166475 (USP 5,528,118), the reaction force generated by the movement of the substrate stage is not mechanically transmitted to the projection optical system using a frame member. You may escape to the earth.
As described in JP-A-8-330224 (USP 5,874,820), the reaction force generated by the movement of the mask stage is not mechanically transmitted to the projection optical system using a frame member. You may escape to the earth.

  The exposure apparatus of the present embodiment is manufactured by assembling various subsystems including the respective constituent elements recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. The In order to ensure these various accuracies, before and after assembly, various optical systems are adjusted to achieve optical accuracy, various mechanical systems are adjusted to achieve mechanical accuracy, and various electrical systems are Adjustments are made to achieve electrical accuracy. The assembly process from the various subsystems to the exposure apparatus includes mechanical connection, electrical circuit wiring connection, pneumatic circuit piping connection and the like between the various subsystems. Needless to say, there is an assembly process for each subsystem before the assembly process from the various subsystems to the exposure apparatus. When the assembly process of the various subsystems to the exposure apparatus is completed, comprehensive adjustment is performed to ensure various accuracies as the entire exposure apparatus. The exposure apparatus is preferably manufactured in a clean room where the temperature, cleanliness, etc. are controlled.

  As shown in FIG. 8, a microdevice such as a semiconductor device includes a step 201 for designing a function / performance of the microdevice, a step 202 for manufacturing a mask (reticle) based on the design step, and a substrate which is a base material of the device. Manufacturing step 203, exposure processing step 204 for exposing the mask pattern onto the substrate by the exposure apparatus EX of the above-described embodiment, device assembly step (including dicing process, bonding process, packaging process) 205, inspection step 206, etc. It is manufactured after.

It is a schematic diagram which shows the structure of the exposure apparatus which concerns on this invention. It is detail drawing of the stopper system in a 1st mount. It is a longitudinal cross-sectional view of a self-weight canceller mechanism. It is a perspective view which shows schematic structure of a wafer stage. It is detail drawing of the stopper system in a wafer stage. It is an expanded sectional view near the projection optical system tip. It is a figure which shows schematic structure of the exposure apparatus of another form. It is a flowchart figure which shows an example of the manufacturing process of a semiconductor device.

Explanation of symbols

EX ... exposure apparatus, PL ... projection optical system, R ... reticle (mask), W ... wafer (substrate), 1 ... first immersion mechanism (liquid supply apparatus), 40 ... wafer stage (substrate stage, moving stage), 58 ... Self-weight canceller mechanism (second support device), 70, 80 ... Gas supply system (exhaust device), 180 ... Space (second gas chamber), 300 ... Air mount (first support device), 300a ... Air chamber ( (First gas chamber), 310, 320 ... stopper system (regulator)

Claims (10)

An exposure apparatus that exposes an image of a pattern onto a substrate by a projection optical system using a moving stage,
A first support device that supports the projection optical system by the pressure of the gas supplied to the first gas chamber;
A second support device for supporting the moving stage by the pressure of the gas supplied to the second gas chamber;
An exposure apparatus comprising: an exhaust device that prevents the projection optical system and the moving stage from interfering with each other by making the exhaust amount of the first gas chamber different from the exhaust amount of the second gas chamber. apparatus. The exposure apparatus according to claim 1, wherein
The moving stage has the substrate mounted thereon,
The exposure apparatus is characterized in that the exhaust amount of the second gas chamber is larger than the exhaust amount of the first gas chamber. The exposure apparatus according to claim 1 or 2,
A detection device for detecting a relative position between the projection optical system and the moving stage;
The exposure apparatus is characterized in that the exhaust amount of the first gas chamber differs from the exhaust amount of the second gas chamber according to the detection result of the detection device. In the exposure apparatus according to any one of claims 1 to 3,
An exposure apparatus comprising a restriction device for restricting movement of at least one of the projection optical system and the movable stage. In an exposure apparatus comprising a substrate stage for placing a substrate and a liquid supply device for supplying a liquid to the substrate, and exposing a pattern to the substrate through the liquid,
A first support device for supporting the liquid supply device by the pressure of the gas supplied to the first gas chamber;
A second support device for supporting the substrate stage by the pressure of the gas supplied to the second gas chamber;
An exposure apparatus comprising: an exhaust device configured to make the exhaust amount of the second gas chamber larger than the exhaust amount of the first gas chamber to prevent interference between the liquid supply device and the substrate stage. apparatus. The exposure apparatus according to claim 5, wherein
A projection optical system for projecting the pattern onto the substrate;
An exposure apparatus, wherein the liquid supply apparatus is mounted on the projection optical system. The exposure apparatus according to claim 5 or 6,
The exposure apparatus according to claim 1, wherein the liquid supply device stops the supply of the liquid when an abnormality of the exposure device is detected. In the exposure apparatus according to any one of claims 5 to 7,
A detection device for detecting a relative position between the liquid supply device and the substrate stage;
The exposure apparatus, wherein the exhaust device makes an exhaust amount of the second gas chamber larger than an exhaust amount of the first gas chamber according to a detection result of the detection device. In the exposure apparatus according to any one of claims 5 to 8,
An exposure apparatus comprising a regulating device that regulates movement of at least one of the liquid supply device and the substrate stage. In the exposure apparatus according to any one of claims 1 to 9,
The evacuation apparatus performs the evacuation operation when an abnormality of the exposure apparatus is detected.

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